While good housekeeping and efficient air filtration are important for reducing mold allergens, the best home air-cleaning system also incorporates biocide chambers with the disinfecting power of ultraviolet (UV) light. The germicidal properties of UV light have been known since the early 20th century. By the 1930s, UV lamps were in use sterilizing air in operating rooms. Biocide chambers bring UV technology to your home cooling system and aim it directly at the source of many indoor air quality problems: the evaporator coil.

A typical evaporator coil looks like the master plan for a mold colony. Condensation in tiny, dark cooling passages of the coil mixes with a continuous airstream of fugitive spores that escape filtration and microscopic organic particles -- better known as mold food. This environment forms a perfect breeding ground for mold. Certain bacterium like Listeria (a notorious source of food poisoning outbreaks) are particularly likely to thrive in evaporator coils.

UV lamps installed in return ducts neutralize some circulating mold spores. However, the air velocity in ducts is so high these moving targets typically don’t receive sufficient exposure. Treating stationary mold on the surfaces of the coil with continuous germicidal UV light is the best home air-cleaning system. Only biocide chambers with multiple lamps mounted above and below the coil saturate all the tiny passageways with mold-destroying ultraviolet light.

Its benefits can be impressive:

Since the home's entire air volume circulates through the evaporator coil, sterilization with biocide chambers promotes a whole-house solution to issues caused by airborne microorganisms.

Allergy and asthma symptoms triggered by airborne mold spores may decrease. The risk of illness from H1N1 and other influenza and cold viruses may also reduce.

Killing coil-clogging mold can increase system airflow up to 15 percent and saves energy.

Disinfecting the evaporator decreases downstream contamination. This includes mold growth in the drip pan that clogs drain lines, as well as the spread of mold colonies to supply ducts.